Where is the tempering error(s)?

Hello,

I have been tempering for while. Beans from Grenada worked perfect. But recently I'm having problems. I use a 20Kg tempering machine with rectangular tank and revolving disk to mix. I then place the molds in the fridge at about 8 C. When I take them out and unmold, all bars are shinny and great. But after one day some become bloomed and pale and develop a powdery texture. What puzzles me is that within the same 4 bar mold, 2 could be perfet and 2 bad. 

The chocolate is made with Hispaniola beans (low butter content) and yes, there is humidity as I'm doing this in the ODminican Republic. Any idea of what I'm doing wrong? Thanks for your help

temperBAD.jpg  •  452KB

Could you describe your tempering process?

How do you check if chocolate is tempered correctly?

What is the temperature of your moulds before depositing chocolate?

Yes, understanding the process helps. I follow instructions in my temerping machine booklet. May be there is good adivise in it for you: https://www.krebsswitzerland.com/image/data/Mktg_PDFs/chocMELTER_6KG_manual_low_res.pdf

Hi Antonio,

I don't want to sound harsh but:

1. You are looking for help with a tempering problem.

2. I have asked a few questions that may help to find the solution.

3. You have not bothered to answer these questions but posted a link to a chocolate melter. This machine will only melt the chocolate and will not temper it.

I'm not sure if you have posted a wrong link (hopefully).

Could you please look at my questions again and try to answer them.

Peter

Peter,

I think you're confusing two different people (the second poster was not the original poster) - I made the same mistake initially.

I may be guilty of that.

My apologies.

Peter, please allow me to "troll" this topic a bit.  Specifically, could you address the mold temperature question?... i.e., should it be close to the temp of the chocolate when first poured into it?  (to avoid "shocking" it... that's my gut-feel anyway)  I'm a rookie and would appreciate any insight.  Many thanks!

Mould temperature should be just below the temperature of tempered chocolate.

In very simplified terms.

Correctly tempered chocolate has only one type of cocoa butter crystals with melting point above 31C. Only some of the cocoa butter is crystalized (seed crystals) and the rest is still liquid. These seed crystals are small and spread throughout the whole mass. When we pour the chocolate into moulds and start cooling we hope that our seed crystals will grow and whole mass will crystalize in the same crystaline form.

If the moulds are much colder than our tempered chocolate some of the remaining liquid cocoa butter will be cooled too fast by the mould surface and in this area we will create crystals with a lower melting point which will result in bloom.

If the moulds are much warmer then tempered chocolate our seed crystals will melt at the mould surface and this part of chocolate will later (during cooling) crystalize in "uncontrolled" manner. It will be difficult to take it out of moulds and it will bloom later.

I hope this helps a little.

I can try to explain in much more detail if needed.

I've previously read advice to put moulds in a refridgerator immediately after pouring the chocolate to "set it." Is this wise or a best practice technique? If this is an ok practice, what conditions (specifically temperature and humidity) within the fridge are recommended?

You mention that they develop a powdery texture, and that you have high humidity.  Look for sugar bloom.  When you hold the bar, does the bloom remelt or remain, and when tasting the surface is it the dry powder you describe.  To prevent, after you cool the chocolate, let rewarm gradually, keeping product above the dew point for room conditions.  It doesn't take much moisture to condense on the surface to cause the problem.

I'm commenting on this thread b/c I think we have a similar problem (our exterior environment is not as humid right now (in a few months it will be high) but still perhaps too much & too high of room temp.) For our last few batches (and after reading this as well as other sources), I believe we have lots of sugar bloom - white dots, tackiness, and crumbliness. We've been following the practice of putting the moulds into the fridge to "set" the crystals in the chocolate. Is this the best practice to use in the first place? However, I do think it is when we take it out of the fridge to room temperature (70F) that the problem arises. Would 65F room temp be reasonably low enough for the moulds & chocolate to come back up gradually? Or, could we leave the moulds out at that or another temperature and avoid the fridge all together?

The speed you cool the chocolate is key to keeping in temper.  When the chocolate is tempered, only ~3-5% of the cocoa butter is crystallized.  Doesn't sound like much until you realize shortening is only about 15%.  If these seed crystals are small and well dispersed you're at ideal temper.  When cooling you want it to be gradual enough to pull the heat created with further crystallization and slowly cool.  If it cools too quickly it will start forming unwanted crystals, typically type IV, causing early fat bloom.  Once set you gradually warm back to room temperature.  Sugar bloom is initiated when the surface temperature of the chocolate is below the dew point temperature for the room.  You see it on the surface of a glass of ice water.  This moisture formed will start to dissolve the sugars.  One percent moisture will create three percent syrup.  This surface syrup then dries out and crystallizes, giving you the sugar bloom.

This has been fascinating and I've learned so much from this one thread. And for all the technical conversation, I'm getting that two things may be happening with Alain's chocolate:

• His molds may be too warm when he pours the chocolate in them, which is likely because it is hot in the Domincan Republic and that is where he is making the chocolate. (Peter, I had never known about this, or thought about it, but it makes so much sense - thanks for the info!)
• The fridge often has too much moisture. When chocolate is placed in the fridge during a humid season, it only makes the situation worse.  You can only use the fridge for short periods of time to shrink the chocolate and release it without spots, or moisture will accumulate and the chocolate becomes 'sticky', then bloom happens when it dries. But sometimes, if humid & hot weather, the fridge is not an option at all for me (I realize in Canada that I only have a 2-month window for this to be a problem  )

Hopefully you can solve your tempering troubles soon Alain!

The problem in this case has nothing to do with mold temperature, or fridge temperature, or even humidity.  It has to do with the type of crystal the cocoa butter has formed in the tempering cycle.

I've seen this happen many times when I'm teaching a new employee to temper chocolate.  They go through the tempering cycle too quickly, and then bar up the chocolate.  The bars at first come out of the cooler with a super nice shine, but within 24 hours, the inside of the bar turns all grainy, and eventually all look exactly like the photo.

Solving this problem is very simple.  When taking the chocolate through it's tempering cycle either:

1. Lower the cooling temperature a couple of degrees (allowing more crystal propogation)or
2. Let the chocolate remain at the cooling temperature for a longer period of time.

The problem you are having is that you are not allowing enough time for the appropriate types of crystals to propogate, BEFORE you reheat yoru chocolate to the working temperature to mold up your bars.

You also need to remember that when working with different kinds of beans and making single source varieties of chocolate, the cocoa butter in each will exhibit different behaviours, and will temper slightly differently from the others.  The tempering cycle is more of a "rule of thumb" for tempering all chocolate, but with experience, you will see that each chocolate you make will temper slightly differently.  It's not something you can just apply a boiler plate heat/cool/reheat cycle to (although for small batches you will get VERY close).

I hope this helps.

Cheers and Happy Chocolate Making!

Brad

I want to thank you all for these extremely useful comments, explanation, tips and remedies. Brad's comment stressing that there is no boiler plate and that "rule of thumb" is the guiding principle is a perfet conclusion. I have reached succes about 50% of the time so far, with better results with fatter beans from Granada and Trinidad in which I do not add cocoa butter. The Dominican beans are rather "dry" and I add up to 8% butter. I do leave the chocolate at 29 degre C for 2 hours before warming it up again and I leave the mould in the open in an A/C room at approx. 22 degres, but not under the fan. That works betes so far. Thank you again